The overall goal of this cooperative research program is to develop a multi- institutional research effort to address the mechanisms of postnatal lung pathobiology that lead to chronic lung disease and to provide a unique resource center of prematurely delivered baboons with induced bronchopulmonary dysplasia (BPD) and chronic lung disease (CLD) to outstanding investigators from multiple institutions dedicated to sharing collaborative protocols and tissue specimens. In recent years, the original form of BPD described in the 1960's has become less common due to improvements in oxygenation and ventilatory strategies and the use of postnatal exogenous surfactant, and has been replaced by a less severe from of disease primarily in extremely small immature infants, called chronic lung disease of infancy (CLD). The baboon models of BPD and CLD are unique in the world; they develop disease that is very similar, if not identical, of human disease but in a controlled environment. The Southwest Foundation for Biomedical Research and the University of Texas Health Science Center at San Antonio have the breeding colony and the scientific personnel to support the proposed BPD Resource Core. The specific aims of the BPD Resource Core are: 1) To breed baboons to produce pregnancies of known gestational ages, and to delivery by caesarian section 100 timed pregnancies per year, to provide the premature infants that will be shared by multiple investigators. 2) To maintain these premature infant baboons in a neonatal intensive care environment for short periods of up to 14 days, utilizing several well-defined treatment protocols, and long-term outcomes in 1 to 2 month and 42 week survivors, the latter the baboon equivalent of a 2 year old human infant in whom alveolarization should be complete. 3) To provide tissue specimens taken at the time of delivery, during the animal's clinical course, and at necropsy in as ideal and timely a manner as possible, and tailored to each investigator's needs. 4) To provide a Data Management Core for animal information retrieval. This U-10 program brings together the enthusiasm and competence of established investigators with varying backgrounds and expertise who are committed to examining the various aspects of lung development and how, when interrupted, the fetus adapts to the extrauterine environment. It allows, at a national level, a continuing influx of outstanding scientists to address the major deficiencies in our knowledge concerning BPD/CLD.